THE DISTRIBUTION OF FEllNS 207 



is less structiir;il difference between the recognizable representatives 

 ot* Conifers, C\ycacleie, Lycopodiaceae, etc., and Dicotyledons of the 

 chalk and those of the pi-esent day, than between the animals of those 

 periods and their living representatives, appears to me a very remark- 

 able fact." The unfolding of plant-life viewed through the distorting 

 mists over the successive stages of earth-history, takes the form of a 

 series of outbursts of energy; the records of one period tell us 

 nothing, while those of the next reveal a fresh type of vegetation, or 

 it may be, a single genus in j^ossession of widely-scattered regions of 

 the world. We seem unable to do more than observe the completed 

 results ; the beginnings are hidden from us, and the farther we 

 penetrate into the past the farther into the distance recedes the object 

 of our search. 



There was no intention to connect the Mesozoic records with the 

 Palaeozoic ; between the two there appears to be a wide gulf. The 

 difficulty of making direct contact between the age of Pteridosperms 

 and the succeeding age of Ferns, may be largely due to the difficulty 

 of determining whether a Palaeozoic fern-like frond should be classed 

 as a Pteridosperm or a true Fern ; but, on the other hand, the relation- 

 ship between the two ages may not be so close as it is usual to 

 assume. In the latter part of the Triassic period, we seem to pass 

 with remarkable suddenness to a new phase of jjlant evolution ; the 

 old order gives place to the new ; one cycle is completed and another 

 has begun. This transformation in the plant world may be intimately 

 associated with some far-reaching event in the physical historj'' of the 

 earth's crust. It may well be that crustal foldings in the latter part 

 of the Palaeozoic era, and the prevalence of desert or semi-arid 

 conditions over wide regions during a part of the Triassic period, 

 were factors which influenced the progress and direction of plant 

 development. 



As continental areas shifted and land and sea changed places it 

 needs no geological knowledge to grasp the fact that tlie rocks ac- 

 cessible to investigation cannot give us all the clues we seek ; parts of 

 old continents remain ; others are bevond oui* reach. 



GEORGE ALFEED HOLT 

 (1852-1921). 



On December 19th, 1921, died at Sale, Cheshire, George Alfred 

 Holt, a man who would ])robably have made his name as a distin- 

 guished cryptogamic botanist, if his eyesight had not suddenly failed 

 him. 



Born in Douglas, Isle of Man, on May 18, 1852, he served his 

 apprenticeship to a chemist in Douglas, and came to Manchester 

 aljout the year 1880, entering into partnership with another chemist. 

 Being fond of botany, he soon got into touch with the leading 

 botanists of the neighbourhood ; he was a constant companion of 



